Heat-coil.



No. 854,272. PATENTE-D MAY 21, 1907.

P. B. 000K.

HEAT COIL.

E APPLICATION FILED NOV. 7, 190a.

VWZrzsSes: 1127/67: Z07:

FRANK B. COOK, OF CHICAGO, ILLINOIS HEAT-COIL.

Specification of Letters Patent.

' Patented May 21, 1907.

Application filed November '7. 1903. Serial No. 180,200.

To all 1071,0172, it may concern:

Be it known that I, FRANK B. COOK, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improve.- ments in Heat-Coils, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to a heat coil, my object being to provide an automatic, selfrestoring coil, adapted to be used as a protective device for electrical circuits.

Heat coils generally in use, are of such a nature that after they have been operated by an abnormally strong current, their members are in such a. condition and position, relatively to each other, that the said coils are not incondition for immediate use, and therefore haveto be replaced by other coils. I have in mind, heat coils in which certain portions thereof are disintegrated by the heat produced in the coil, by abnormally strong currents therein, the saidportionsnot returning to'thir normal, relative positions.

when the coil has cooled. Such coils are inconvenient and expensive as they necessarily have to be replaced by other coils, after they have operated.

In my resent invention, I have shown a heat coil 1n which all of the parts have the same relation to each other, after the coil has been operated and cooled, as they normally had before the operation of the coil. For this reason, the same coil may be used over, again and again, it being in the same condition as originally. This is a great sav' ing in maintenance, and is also very convenient, especially Where a large number of circuits are to be protected.

,This present inveption may be adapted and applied to various forms of circuits and under various conditions, but it is particularly adapted to telephone lines and systems where protection of delicate instruments is a very essential necessity. In large telephone systems, where a great many circuits are to be protected, the space occupiedby protective apparatus is of great importance, and I have therefore endeavored to make this heat coil a compact and efficient arrangeof electrical circuits wherein protection from abnormally strong currents is desired.

In this present invention I ,employ a heatconducting member, upon which the coil proper is wound, and end pieces, which, withv the heat-conducting member, form a spool for containing the said coil. One'end of the spool is permanently secured to the core of the spool While the other end is secured to the said core by a fusible material. This core is the above mentioned heat-conducting.

member, and through it the heat from the coil is conducted to the fusible material;

When the fusible material is softened, it allows the relative position of the core and end of the spool containing the fusible Ina-- terial, to, change, and thereby, cause the the operation of the coil, it may open a cir cuit, close a circuit, or do both, as is required;

but under all conditions the arrangement must be such that the parts of thecoil are restored to their normal, relative position, immediately after operation. g

The invention herein, lies particularly in the combination of the heat-conducting core, fusible material, s ool end, coil for producing heat, and means or restoring these parts to their relative, normal position, after operation, as shown in the accompanyinmdrawings, and as will be hereinafter described.

Another feature of this invention is the method by which the core of the spool is permanently secured to, and insulated from, one end of the said spool.

I will more particularly describe myinven tion by reference to the accompanying drawingbs, in which 7 r igure 1 is a side View of the heat coil, somewhat enlarged; Fig. 2 is an end view of the said coil, taken from Fig. 1; Fig. 3 is a sectional view of the heat 0011, taken on line E F of Fig. 2; Fig. 4 and Fig. 6 are views showing theheat coil in service, in combination with: its means of operation and restoration; Fig. 5 and Fig, 8 show a modified form of- Figs. 4 and 6, the modification being in the springs of the arrangement; and Fig. 7 is a view showing the heat coll in service, 1n an operated position.

Like characters refer to like parts inthe several figures.

- The heat coil as a whole, is best seen in Fig.

1 where it is shown in its entirety; 'In Fig. 3 it will be seen that the coil proper Zr, is Wound upon ametal core a. The coil- 70 furnishes means for producing heat, and the core 6 acts as a' conductor of this heat, conveying it to where it 18 to be utilized. The core e is prov vided with two annular projections thereon,

one at 0 and oneat h. The part ois held be tween two insulating disks, or washers, n and m. The metal disk f is supplied with a hollow cylindrical projection Z which is a part of f. In this hollow oylind er Z, is held the insumay be split before it is ,put in place.

also be noticed that the outside diameter of 0 is considerably smaller than the inside diamet'er of Z. The conical-shaped projection g is attached tof and is preferably apart thereof.

The end. cap B, Fig. 1, is composed of two annular projections, or flanges, b and (Z, and the cylindrical portion 0 which is centrally bored as shown at r, Fig. 3. The cap B is made of metal. The annular projection h'fits loosely in the bore 7', against a shoulder at the inner end. of r, and is held thereto by a solder which is shown at i. There is enough play between 72/ and r so that when the solder tis melted or softened, the turning motion of Zr, in-r, with one point ofi as the fulcrum, is considerable. The ends p and q of coil is are soldered to parts 0 and Z, respectively. The coil Zc is en-. tirely inclosed by the hollow cylindrical casing a, of insulating'material. -'The casinga fits loosely between I) and f, on its end surfaces, in order not to interfere with the motion of h, in 1', when the solder i is softened.

In assembling the device, the end cap B is first threaded upon the core 8 by passing the annular projection 0 through the hole in the inner end of the cap B. Then washer n, annular projection 0 and split washer m are placed within the cap-shaped portion of end cap f which is then formed over as at Z to firmly hold a, 0 and m there n} 1" by an easily fusible solder i, after which the winding Zr is wound upon the core e and the ends q and p of winding Zc soldered to end It will The annular projection h is then soldered within the bore In Figs. 4 and 6, the heat coil is shown in service. The springs t and u are the springs to which the respective circuit wires 1 and 2, of the circuit to be protected, are connected. A portion of spring t is cut away, to show the provided with a slot in its upper end for re ceiving one end of the heat coil. Spring .9 is a ground plate, conductor 3 connecting s with the ground. Springs t, u. and sure mounted on a suitable support c. When the heat coil is put in place, the cap B is first inserted in the slot in spring a, the spring a passing between the flanges Z) and (Z. The conicalshaped. projection g is then depressed and inserted through the conical-shaped hole t, in spring 25. The diameter of the conicalshaped hole t is somewhat larger than the diameter of g, so as to allow 7 to pass through the hole t easily. Inserting g through the hole t,, puts a bend in spring a and thereby causes the upper surface of g to engage the upper surface of the hole 25,, the two conical The heat coil is now in position for protecting the circuit of which springs 13 and u are a part. .The currents traversing the circuit. 1 2, also traverse spring t, projection 9, disk f, cup Z, winding Zc, cap B and spring a. When a strong current traverses this circuit, it heats the winding Zc of the heat coil, and. this in turn heats the metal core (2. The heat from c is conducted through the flange Zr to the fusible material i. When this heat is sullicient, it causes the fusible material i to soften, thus allowing the ilange ft to move in the bore 1' of cap B. This allows the projection g to drop.

\AlOWH inthe hole t,, and the spring a to straighten somewhat, thus reducing the pressure between the surfaces of g and t,. WVhen this pressure is sul'liciently reduced, the pro jection g slips out of the hole t,, and the spring it takes the position shown by the dottedlineu of Fig. 6, or more clearly in Fig. 7. I/Vhen the heat coil takes this new position it opens the circuit between'l and 2, at g, and. closes the circuit between 2 and 3, where the core e comes in contact with ground spring 8. Thus it will be observed that if the instru ment to be-protected is included in circuit wire 1, and the strong current comes from circuit wire 2, the operation of the heat coil strument in 1, and connects thisstrong current to ground at 3, thus protecting the instrument in 1. In other words, the strong current from 2, is switched from 1 to 3.

core e strikes the ground plate 8, the position of the flange Zr, relatively to the cap B, is brought back to the normal, by this contact; and as soon as the fusible material cools, the

flange h is soldered to the cap B, as it was originally. The pressure between core 0 and surfaces forming a catch for holding g to t,..

As soon as the heat coil operates. and the method employed for holding the conicalshaped projection g, in spring 25. Spring 'u is,

breaks the strong current of 2, from the inspring .9, due to spring 41., holds the flange h in place, while the solder 'i cools.

In Figs. and 8, I have shown a modified form of the arrangement shown in Figs. 4

and 6. The modification is in the spring a, which is secured to spring u Spring a, in Figs. 5 and 8, corresponds to spring a in Figs. 4, 6, and 7. In Fig; 8, the spring a, rests against the end of core 6. When the heat coil operates, as described above, the spring a, presses the flange it back to its normal position before connection is made between springs u, and s as shown in the dotted line view a, of Fig. 8. As spring a, is a light spring, it does not interfere with the opera tion of the heat coil when the projection g releases from hole t, of spring t; it merely helps to restore it to its normal position and to make good contact between end cap B and spring u,.

While I have described particular details of construction in this invention, I do not wish to limit myself to such details. I therefore Wish it to be understood that the invention herein, lies'in the principles of action of the heat coil,'more particularly than in the details of construction.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is'

1. In a heatcoil, the combination of a heat-producing member, a heat-conducting member, a fusible material securing the heatconductingmember to' another conducting member, and means apart from the heat coil, by which the members of the heat coil are restored to their normal,relative osition, after.

the fusiblematerial has been so tened.

2. In a heat coil, the combination of a heat-producing member, a heat-conducting member, a fusible material, a centrally-bored, conducting member secured to the heat-conducting member by the fusible inaterial, and means apart from the heat coil, whereby the members of the heat coil are restored to their normal, relative position, after the fusible material has been softened. V 3. In a heat coil, the combination of a heatroducingmember, a heat-conducting mem er, a centrall -bored, conducting memher, through which the heat-conducting inember asses, and a fusible material which secures the heat-conducting member to the centrally-bored, conducting member, as de-' scribed.

' 4'. In a heat coil, the combination of a heat-producing member, .a heat-conducting member, a centrally bored, conducting mem her, through which the heat-conducting member passes, a fusible material by which the heat-conducting member is normally secured to the centrall -bored, conducting member, and means whereby the members of the heat coil are restored to their normal,

relative position, after the fusiblematerial has been softened.

, 5. In a heat coil, the combination of a heat-producing member, a heat-conducting member, a centrally-bored member through which the heatconducting member passes, a f

ment, and means apart from the heat coil, by

which'the heat-conducting element and centrally-bored element are restored to their normal, relative position, after the fusible material has been softened, thus allowing their relative positionto change, substantially as described.

- 7. In a heat coil, the combination ofa heat-conducting element, a heat-producing element, a centrally-bored element, the heatconducting element being inclosed by the heatreducing element and the centrallybore element, and secured to the centrallybored element by a fusible material, and

-means apart from the heat coil, whereby the relative positionsof the elements of the heat coilare restored to the normal, after being allowed to change by the fusible material becoming softened, substantially as described.

8. In a heat coil, the combination of heat-producing coil, a heat-conducting memher, two centrally-bored, conducting members, the heat-conducting member being in closed by the heat-producing coil and the two centrally-bored members, and being secured to one centrally-bored member and insulated therefrom, and secured to the other centrally-bored member by a fusiblemate fl rial, and means whereby the relative position. of the members of the heat coil is restored to the normal, after being allowed to change by thesoftening of the fusible material, and secured by the fusible material hardening, substantially as described.

9. In a heat coil of the character described, the combination of aheat-producing coil, a heat-conducting core for the said coil, two centrally-bored, conducting members, forming ends of a spool of which the said heatconducting core is the core, the said core carrying two annular projections which are inclosed in the respective centrally bored members, one annular projection being secured to and insulated from one centrallybored member, by insulating washers, one on each side of thesaid annular projection, the other annular projection being conductively secured to the other centrally-bored member, by a fusible material, and means whereby, after the fusible material has been softened, thus allowing the relative position of the members of the heat coil to change, the normal, relative position of the members of the heat coil is restored, and secured by the fusible material becoming cool, substantially as described. j

10. In a heat coil of the character described, a heat-producing element in the form of a coil, a spool for this coil, consisting essentially of two conducting end pieces and a conducting core normally secured thereto,

the said end pieces being centrally-bored to receive respective annular projections of the said core,one annular projection being secured to and insulated from one centrallybored end piece, by insulating washers, one on each side of the annular projection, the other annular projectionbeing secured to the other centrally-bored end piece by a fusible solder, a lug of conducting material secured to the outer surface of one end piece, a sleeve of insulating material inclosmg the said spool from one end piece to the other, and] means for operatlng and restoring the heat coil, substantially as described.

11. In combination, as a protective device for electrical circuits, a heat-producing element inclosing a heat-conducting core, two centrally bored, conducting elements to which the said core is secured, the said core being insulated from one centrally-bored element, and conductively secured to the other by a fusible material, the centrally-bored elements being terminals for the hea -producing element, a lug secured to the outer face of one 'cen trallybored element and adapted to engage a spring, a second spring adapted to engage the other centrally-bored element, a suitable base for the said springs, the said fusible material being heated and softened by an abnormally strong current traversing the heat-producing element, thereby allowing the norn'ial, relative position of the elements of the heat coil to change, and the said lug to release itself from the spring engaged there- .with, and means cooperating with the said second spring when it operates, whereby the normal, rclative positions of the said elements are restored before the fusible material has cooled, substantially as described.

12. In combination, as a protective device for electrical circuits, a heat-produ ing coil wound around a heat-conducting core, two centrally bored, conducting elements to which the said core is secured, the said core being insulated from one centrally bored element, and conductively secured to the other by a fusible material, the'centrally-bored elements being terminals for the heat-producelements of t with a slot therein and adapted-to receive the'other centrally-bored element, a third I spring used as a 'ground connection, a suitable support to which the said s rings are secured, the said fusible material Iieing heated and softened by an abnormally strong current traversing the heat roduci ng coil; thereby allowing the normal: relative. position of the elements of the heat coil to change, and thereby causing the said lug to release itself from the hole in the spring engaged therewith, the action of the said second spring causing the said core to engage the said ground s ring and thereby restore the lie heat coil to their normal, relative position, where they are held by the. fusible material becoming hardened, substantially as described.

13. In combination, as a protective device for electrical circuits, a heat-producing coil Wound upon a heat-conducting core, two centrally bored, conductim elements to which the said core is secured, one provided with an annular groove therein and the other provided with a conical-shaped lug secured thereto, the said core being insulated from one centrally-bored element, and conductively secured to the other by a fusible solder, the centrally-boredelements being terminals for the heat-producing coil, a

and ground plate are secured, the fusib e 1naterial being heated and softened by the heat conducted thereto by the said core when an abnormally large current traversesthe said heat --producing coil, thereby allowing the said core to move in one centrally-bored element and thus cause the said lug to release itself from the hole in the spring engaged therewith, the action of the second mentioned spring causing the said core to come in contact with the ground plate, thereby restoring the said core to its normal position in the said centrally-bored element to which it was soldered, and changing the circuit from the said springs and heat coil, to the second mentioned spring and ground plate, substanwhich the said core is secured, one provided with an annular groove therein and the other'provided with a conical-shaped lug secured thereto and forming a part thereof, the said core being insulated from one centrallybored element, and conductively secured to the other by a fusible solder, the centrally- 7 bored elements being terminals for the heat with a beveled hole t producing coil, two springs, one provided erein and the other provided with a slot therein, the said springs being adapted to normally engage the re- 'spective centrally-bored elements, at the said groove and lug thereof, a third spring secured to the spring provided with a slot, and resting against oneend of the said core, a ground plate, suitable support to which the said springs are secured, the fusible material being heated and softened by the heat conducted thereto by the said core, when an abnormally large current traverses the said heat-producing coil; thereby allowing the said core to move upon its soldered support and thus cause the said lug to release itself .from the spring engaged therewith, this ac- I tion causing the last mentioned said spring .to engage the ground plate, thereby breakmg the circuit between the first mentioned springs and closing acircuit between one of the first mentioned springs and the ground plate, the said third spring causing the said core to be restored to its normal position upon its soldered'support, and secured thereto by the cooling action of the fusible solder, substantially as described.

15. In an electrical circuit protector the 18; In airelectrical circuit protector, a heat cartridge provided with a central sp1n.' dle having'a solder connection with the cartridge in combination with means for placing said spindle into position for resoldering.

19. In an electrical circuit protector, a heat cartridge provided with a central spindle having a solder connection with the cartridge, means for heating and softening saidsolder connection on the passage 'of'an unduly strong current, and means for placing said spindle in position for resoldering:

20. In an electrical circuit protector, a heat cartridge provided with a centrally disposed movable member having a solder connection with the cartridge, means for softening said solder on the passage of an unduly strong current to permit movement of; saidmember, and means for placing said member in position in which the solder connection can be hardened, whereby the central member will be resoldered.

21. In an electrical circuit protector, a heat cartridge'provided with a centrally disposed movable member having a solder con- 'nection with the cartridge, means-for softening said solder on the passage of an unduly strong,current to permit movement of said member, and means apart. from the heat" coil for placingfsaidmember in position in which the solder connection can be hardened, whereby the central member will be re-' soldered.

22 In an electrical circuit protector, a heat cartridge comprising a centrally disposed movable member having a solder connection with the cartridge, a heat coil surrounding said central member, and, means for placing said member in position to pernut it to be resoldered after the solder has been softened by heat generated in said heat coil. L

In witness whereof I hereunto subscribe my name this 5th day of November, A. D.

FRANK B. 000K.-

Witnesses: FRED. R. PARKER,

' HARRY B. ELMERS. 

